1. Field of the Invention
The present invention relates to patient monitoring and/or treatment. Although embodiments make specific reference to monitoring impedance and electrocardiogram signals with electrodes, the system methods and device described herein may be applicable to many applications in which patient monitoring and/or treatment is used, for example long physiological monitoring and/or treatment with implantable devices.
Patients are often treated for diseases and/or conditions associated with a compromised status of the patient, for example a compromised physiologic status. In some instances, a patient may report symptoms that require diagnosis to determine the underlying cause. For example, a patient may report fainting or dizziness that requires diagnosis, in which long term monitoring of the patient can provide useful information as to the physiologic status of the patient. In some instances a patient may have suffered a heart attack and require care and/or monitoring after release from the hospital. One example of a device to provide long term monitoring of a patient is the Holter monitor, or ambulatory electrocardiography device. In addition to measuring heart signals with electrocardiograms, known physiologic measurements include impedance measurements that can be used to assess the status of the patient. Patients who have sufficiently compromised status may be treated with implantable devices, such as pacemakers, that can provide therapy with electrical pulses delivered through electrodes.
Although current methodologies have been somewhat successful in monitoring and/or treating patients, work in relation to embodiments of the present invention suggests that known methods and apparatus may be less than ideal. In at least some instances, devices for patient monitoring and/or therapy can be expensive, such that some patients do not have access to the these treatments and/or therapies. Also, some of the devices for monitoring and/or treating patients can be complex, such that proper use of the device may be complicated and/or time consuming and may place a burden on the health care provider. In some instances, devices may be complex for a patient to install, such that mistakes may be made and some patients may not be able to use the devices properly for long term at home monitoring.
Therefore, a need exists for improved patient monitoring. Ideally, such improved patient monitoring would avoid at least some of the short-comings of the present methods and devices.
2. Description of the Background Art
The following U.S. patents and Publications may describe relevant background art: U.S. Pat. Nos. 4,121,573; 4,498,479; 4,955,381; 4,981,139; 5,080,099; 5,353,793; 5,511,553; 5,544,661; 5,558,638; 5,673,704; 5,724,025; 5,772,586; 5,836,990; 5,862,802; 5,935,079; 5,949,636; 6,047,203; 6,117,077; 6,129,744; 6,225,901; 6,385,473; 6,416,471; 6,454,707; 6,527,711; 6,527,729; 6,551,252; 6,569,160; 6,595,927; 6,595,929; 6,605,038; 6,645,153; 6,821,249; 6,824,515; 6,980,851; 7,020,508; 7,027,862; 7,054,679; 7,153,262; 2003/0092975; 2004/0243018; 2005/0113703; 2005/0131288; 2006/0010090; 2006/0020218; 2006/0031102; 2006/0089679; 2006/122474; 2006/0155183; 2006/0224051; 2006/0264730; 2007/0021678; 2007/0038038; and 2007/0038078.